Workers, on construction sites, must constantly face problems during the excavation of trenches or the like, some of the problems being due to required variations in substantial degree in the depth and width of the excavation and others being due to the nature of the ground being excavated.
There may be, on the same site, some portions of excavations being effected in a ground having a perfect cohesion at some location, and a lesser or very weak cohesion at another location, such poor cohesion grounds having in some cases the consistency of liquid mud. It is therefore necessary, in order to meet all extreme conditions, to have available different types of lining materials or equipment ready at hand, which results in requiring a heavy capital investment and providing a poor return on the investment, because the materials and equipment are not always systematically and efficiently used; furthermore, the equipment must be constantly maintained and repaired.
A considerable variety of materials and equipment is available on the market, and they may be classified as follows:
(1) Pilings with tie beams welded at their center or at their ends;
(2) Pilings driven in the ground and between which are inserted panels provided with edges interlocking with the piling edges;
(3) Double pilings, either of unitary structure or slidable relative to each other, in engagement with the ground and between which panels are inserted;
(4) Panels on which are welded C-shaped or U-shaped channels adapted to accept the end of struts provided with rollers.
Such a list of diverse equipment, which is far from being complete, shows clearly the great number of different materials that a single construction firm must own or have available to it, because each type of equipment has a well-defined application.
The present invention remedies the inconveniences of the prior art in providing a type of equipment whose usage is so versatile as to solve a great number of problems without necessitating the use of special particular equipment according to the condition encountered in the course of the work.